Exhaust systems for removal of fumes

ABSTRACT

An exhaust system for removal of fumes, gases, vapors and other contaminants from sources of contaminant, such as movable working stations and/or work objects, permits continuous exhaust of contaminant while the working stations and/or work objects are being moved. To this end, communication is established between the source of contaminant and the exhaust fan through fixed duct portions and movable duct portions. These fixed and movable duct portions are interconnected over openings in the fixed duct portions, which openings are kept closed by elastic strips, and over tapping units associated with the movable duct portions, said tapping units being adapted to move aside the elastic strips to establish connection between the fixed and the movable duct portions. The fixed duct portions are arranged along at least certain portions of an overhead track on which run trolleys carrying the tapping units and the movable duct portions.

United States Patent Inventor Erik Allan Lhdkvist Korpralsvagen 4411, 902 53 Umea, Sweden App]. No. 823,601 Filed May 12, 1969 Patented Aug. 31, 1971 Priority May 13, 1968 Sweden 6421/68 EXHAUST SYSTEMS FOR REMOVAL OF FUMES 3 Claims, 7 Drawing Figs.

3,018,503 1/1962 l-lijiyaetal 3,176,971 4/1965 Hilton Primary ExaminerMeyer Perlin Attorney-John Lezdey ABSTRACT: An exhaust system for removal of fumes, gases, vapors and other contaminants from sources of contaminant, such as movable working stations and/or work objects, permits continuous exhaust of contaminant while the working stations and/or work objects are being moved. To this end, c0mmunication is established between the source of contaminant and the exhaust fan through fixed duct portions and movable duct portions. These fixed and movable duct portions are interconnected over openings in the, fixed duct portions, which openings are kept closed by elastic strips, and over lapping units associated with the movable duct portions, said tapping units being adapted to move aside the elastic strips to establish connection between the fixed and the movable duct portions. The fixed duct portions are arranged along at least certain portions of an overhead track on which run trolleys carrying the tapping units and the movable duct portions.

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SHEEI 3 OF 4 CONTAMINANT SOURCE EXHAUST SYSTEMS EUR REMOVAL 01F lFUMlES This invention relates to an exhaust system for removal of fumes, gases, vapors and other contaminants produced in workshops by machines movable in such premises, and at working stations and the like therein. Such exhaust system comprises exhaust fans or like apparatus as well as ducts, pipes and hoses leading to the sources of contaminant, a duct portion which is preferably fixedly mounted in the premises and a duct portion which is movable together with a machine, tool or the like, a tapping unit associated with each such movable duct portion and adapted to establish communication between said fixed duct portion and said movable duct portion through an opening disposed in and extending along the fixed duct portion, and elastic strips are provided along said opening for normally keeping it closed, said tapping unit moving said strips apart when establishing communication between said fixed and movable duct portions.

In many places of work, air contaminants such as fumes, gases, dust particles etc., must be removed and such removal is most favorably carried out at the source of contaminant. The alternative of such a local removal is that the air circulation in the premises is so arranged that the degree of contamination can be kept at an acceptably low level by supply of fresh air and exhaust of contaminated air. In large premises with heavy air contamination this system is not acceptable inter alia for reasons of heat economy and because of the arising cross drafts. One has therefore already suggested the provision of ducts or hoses which have been drawn up to the source of contaminant and thereby produced a certain degree of exhaustion. Systems of this kind as a rule are suited only for stationary machines or working stations or for such machines or stations as are movable within very narrow confines since it is not possible for practical reasons of handling to provide unlimited lengths of ducts and hoses which are fixedly connected to exhaust fans or like apparatus. In order not unnecessarily to complicate the hitherto proposed exhaust installations by the provision of valves or dampers at each exhaust point, such temporarily unused exhaust points in systems having several ducts or hoses connected to a common fan were allowed to remain open, which caused heavy noise and was less desirable also from the viewpoint of power economy. In premises where contaminant-producing work is carried out at several points of an article of large extension or at several different working stations while a contaminant-producing object, such as an automotive vehicle, travels through the premises, the use of fixed hoses or loose hoses that are connectable to fixed connecting points results in a not insignificant waste of time, since at each working station during the passage of the object to be worked a new hose must be pulled in position, or consecutive switching must be effected between various ducts or hoses in order to realize the contemplated exhaust. Nevertheless, no exhaust is obtained while the object to be worked is moving.

The present invention has for its object to provide an exhaust system for fume removal, in which the suction hose can be moved within the workshop premises without necessitating any coupling measures and which can be put in operation wherever this is desired. The characteristic features of the exhaust system reside in that one or more substantially fixed duct portions having a suitably slot-shaped opening are disposed along one or more sections of an overhead track suitably suspended in the premises and that trolleys supporting the tapping units and the associated ducts, hoses or like ele ments connectable to the source of contaminant are adapted to run along said overhead track.

The invention will now be more fully described with reference to the accompanying drawings in which:

P16. 1 is a side elevational view and partial section of one of the tapping units with associated trolley, said tapping unit FIG. 3 is an end view of the tapping unit shown in FIGS. l and 2;

FIG. 4 is a diagrammatic top plan view of the overhead track in one embodiment thereof;

FIGS. 5a and 5b are a top plan view and a side elevational view, respectively, of the overhead track in another embodiment thereof;

FIG. 6 is a top plan view of the overhead track in a further embodiment thereof.

The main constituents of the exhaust system are (a) the overhead track which consists either of exhaust ducts ll having a rail 2, or of a rail 2 supported by a beam or like element 3, (b) trolleys 4 adapted to travel along said rail 2, (c) an optional number of tapping units 5 supported by the trolleys d, and (cl) suction hoses 6 or like means connected to the tapping units 5 and arranged to extend up to the source of contaminant. The exhaust ducts 11 are connected over pipelines 7 to one or more exhaust fans according to the requirements in each particular case, and from these fans the contaminated air is caused to escape into the atmosphere in a suitable way and preferably through filters.

In order that a constant pressure below atmospheric may be maintained in the exhaust ducts 1 the fans should be equipped with a suitable pressure control device. The track may be fixedly mounted in the premises but in certain cases it can also be provided along a pivotally mounted beam, a telescoping beam or like member. 1

How the portions of the track equipped with exhaust ducts are constructed will be most clearly apparent from FIGS. 1-3. The exhaust duct ll proper, which may be made from steel or other suitable material is suspended with the aid of brackets h in a suitable way from the ceiling of the premises or in a supporting structure thereof. Along the upper side of the duct I there is secured a bar which serves as a. rail 2 for the wheels 9 of the trolleys 4 to travel on. Along the downwardly facing side the duct 1, as will appear from FIG. 2, has a number of holes l0. Instead'of aligned spaced holes the duct may, however, present a longitudinal slot. On each side of the row of holes 10 elastic strips 11 are secured by means of bars 12 and locking cords 13. The free edges M of the strips 11 sealingly bear against one another and thus in nonactuated normal p0sition close the duct ll. Due to the fixed marginal portions of the strips lying tangentially to the duct, while the free interengaging marginal portions are at right angles to the duct, the strips will possess a certain bias which produces an initial seal. At a pressure below atmospheric in the duct 1 the strips will be pressed against one another under an increased force so that an improved seal is obtained.

The wheel sets of the trolley 4 include aligned wheels 9 which roll on the rail 2 disposed on top of the duct l, and a pair of opposite wheels 15 which are located at a lower level and take an oblique position relative to one another, side wheels preventing a lateral swinging movement of the trolley because they engage obliquely form [below the periphery of the duct 1 and rails 16, respectively, associated with the supporting beam 3. The tapping unit 5 which is supported by the wheels 9 via yokes 17 extending on one side of the duct 1, comprises a nozzle portion 18 which tapers towards both sides and merges in a preferably cylindrical connecting portion 19 for the flexible suction hoses 6. When the trolley from part of the track composed of only the beam 3 and the rail 2 arrives at a portion of said track which is equipped with an exhaust duct, said laterally tapering and outwardly inclined plough-shaped portion 18 is adapted to move apart the elastic strips M, and when the trolley with the associated tapping unit 5 has travelled inside the end of the strips 11, said strips will close again whereby a substantially tight connection is obtained between the exhaust duct I and the suction hose connected to the tapping unit 5. To facilitate moving the trolley 4 onto the part of'the track equipped with an exhaust duct, guide projections 20 at the end of the duct will ensure that the tapping unit 5 will register with the strips 11. Besides, at the end of the strips 11 there is provided an elastic sealing tongue 21 which permits being moved aside and which seals the space between the strips in the axial direction. Said sealing tongue is adapted to be moved aside by the end of the tapering noule portion 18 and to revert to sealing position between the strips 11 when said portion has passed. A similar sealing tongue is provided at the opposite end of the strips 11.

Buffer means 22 are arranged at the trolleys 4 to prevent that two trolleys will be moved so close together that the tapering nozzle portions 18 will engage each other, as the elasticity of the strips would not be sufficient to close the opening therebetween.

ln premises equipped with exhaust ducts l and overhead tracks, as shown in FIG. 4, the working stations may be placed at will. Trolleys not in use can be kept at some track portion devoid of exhaust duct 1, or at a portion of the exhaust duct which has been separated from the remaining duct by the provision of partitions so that, as need arises, said trolleys can be'movedonto a portion of the track having an exhaust duct 1.

The'overhead track according to FIGS. 5a, 5b is intended for such premises where the sources of contaminant, for ex- 1 ample vehicles powered by internal combustion engines, are

moved in a definite order through the premises. The track is inclined sothat the track end at the end of the path of travel is at a higher level than the opposite track end. By this arrangement the trolleys can automatically return along the rail 2 after they have reached the end of the portion of the track having an exhaust duct.

The form of the overhead track shown in FIG. 6 is constructed for premises with a definite flow of work pieces, and the track permits travel of the trolleys past one another by switches having been inserted in the track.

To reduce the friction between the nozzle portion 18 and the strips 1 l as far as possible a suitable lubricating device, for example a graphite lead, can be provided adjacent at least one edge of the tapering portion 18, or a friction-reducing agent can be deposited on the surface thereof.

To be kept out of the way when not in use, the hose 6 connected to the nozzle unit should be supported by a suitable spring mechanism such as a spring-actuated pulley block which raises the hose when it is released. Finally, the hose should be provided with a safety coupling which opens under overload and prevents too long an extraction of the hose from acting upon the trolley and the tapping unit.

Modifications are possible within the scope of the appended claims.

What I claim and desire to secure by Letters Patent is:

1. An exhaust system for removal of fumes, gases, vapors and other contaminants produced in workshops by machines movable in such premises, and at working stations therein, comprising an exhaust system including exhaust fans, ducts, pipes and hoses leading to the sources of contaminant, at least one duct portion being fixedly mounted in said premises and at least one duct portion being movable together with a source of contaminant; a tapping unit associated with each duct portion and adapted to establish communication between said fixed duct portion and said movable duct portion through at least one opening disposed in and extending along said fixed duct portion elastic strips provided along said opening for normally keeping it closed, said tapping unit being capable of moving said strips apart to establish communication between said fixed and said movable duct portions, wherein at least one of said fixed duct portions which presents an opening is disposed along an overhead track suitably suspended in said premises and trolleys supporting said tapping units and the associated movable duct, connectable to the source of contaminant and adapted to run along said overhead track: closure means mounted at the end of said strips which are movable aside, said closure means in nonactuated position being adapted to axially close the space defined by said strips and the peripheral duct surface surrounding said opening, and wherein said tapping unit tapers towards its ends and has outwardly inclined clipper bow or plough-shaped end portions,

said end portions being adapted when said tapping unit is moved towards and past the strip ends to move aside said closure means inwardly or outwardly respectively and to adjust the strip ends and said tapping unit for alignment with regard to each other.

2. An exhaust system as claimed in claim 1 wherein said overhead track is in the form of a closed path with straight portions connected by curved portions, at least one section of said track consists of a rail for said trolleys to travel on and an exhaust duct, while the remaining track consists of a rail only.

3. An exhaust system as claimed in claim 1 wherein said closure means is an elastic tongue. 

1. An exhaust system for removal of fumes, gases, vapors and other contaminants produced in workshops by machines movable in such premises, and at working stations therein, comprising an exhaust system including exhaust fans, ducts, pipes and hoses leading to the sources of contaminant, at least one duct portion being fixedly mounted in said premises and at least one duct portion being movable together with a source of contaminant; a tapping unit associated with each duct portion and adapted to establish communication between said fixed duct portion and said movable duct portion through at least one opening disposed in and extending along said fixed duct portion elastic strips provided along said opening for normally keeping it closed, said tapping unit being capable of moving said strips apart to establish communication between said fixed and said movable duct portions, wherein at least one of said fixed duct portions which presents an opening is disposed along an overhead track suitably suspended in said premises and trolleys supporting said tapping units and the associated movable duct, connectable to the source of contaminant and adapted to run along said overhead track: closure means mounted at the end of said strips which are movable aside, said closure means in nonactuated position being adapted to axially close the space defined by said strips and the peripheral duct surface surrounding said opening, and wherein said tapping unit tapers towards its ends and has outwardly inclined clipper bow or plough-shaped end portions, said end portions being adapted when said tapping unit is moved towards and past the strip ends to move aside said closure means inwardly or outwardly respectively and to adjust the strip ends and said tapping unit for alignment with regard to each other.
 2. An exhaust system as claimed in claim 1 wherein said overhead track is in the form of a closed path with straight portions connected by curved portions, at least one section of said track consists of a rail for said trolleys to travel on and an exhaust duct, while the remaining track consists of a rail only.
 3. An exhaust system as claimed in claim 1 wherein said closure means is an elastic tongue. 